Driving Algae Sustainability

By Mary Rosenthal | November 20, 2012

Just a few weeks ago, the National Research Council released its report on the sustainability of biofuels derived from algae, affirming the potential of our industry to meet global fuel challenges in a sustainable manner.

The 240-plus page report identified the key areas of sustainability and noted potential concerns with each, yet concluded that none of these barriers were insurmountable with continued innovation. They rightly identified energy returns; greenhouse gas (GHG) emissions; water use; supplies of nitrogen, phosphorus, and carbon dioxide, and appropriate land resources as the issues that could most impact long-term sustainability.

The report concludes, however, that the committee “does not consider any one of these sustainability concerns a definitive barrier to sustainable development of algal biofuels because mitigation strategies for each of those concerns have been proposed and are being developed.”

The fact that algae companies are already developing strategies and approaches to scale production, with a focus on reducing environmental impact, should not come as a surprise to anyone. It is the defining reason for being for every algae company CEO with whom I’ve ever talked—it’s in our DNA. Today’s algae companies don’t simply want to replace petroleum, they want to invent an alternative that performs as well or better, at a cost that is competitive and can be produced all across America.But that’s only half the story. The other real driver for algae sustainability is economics. Simply put, the economic sustainability of algae-derived fuels is inextricably linked to the environmental sustainability. No sustainability, no return on investment (ROI).

There is one reason why we need not worry about algae competing for fresh water resources: it’s too expensive. Every major algae producer today is using brackish, saline or wastewater for the growing medium. This eliminates one key sustainability concern identified by the report.

This is why you won’t see any large algae ponds being placed in large population areas or on lands otherwise suitable for traditional agriculture, or producers flushing costly nutrients and fertilizers downstream, or using significantly more energy than that provided for free by the sun: it would be cost prohibitive. It’s also why you saw algae fuel producers among the first to recognize the value of being able to utilize waste carbon dioxide (CO2) emissions as a key nutrient, low-cost inputs help achieve low-cost outputs.

In addition to competing on cost, algae-derived biofuels have another metric to hit, which is life-cycle reduction in GHG emissions. If producers want their fuels to benefit from the targets for advanced biofuels as stated in the renewable fuel standard, algae-based fuels must reduce CO2 emissions by more than 50 percent compared to traditional fuel. Every algae fuel company in the world will make darn sure its fuel complies with this mandate.

Perhaps the most important sustainability variable is algae’s energy output. The NRC pointed out that algae’s energy return on investment will have to be around three units of energy produced per unit of energy input. Industry leaders are already achieving this by focusing their efforts on improving technology and engineering, reducing water impacts, recycling their nutrients and enhancing other sustainability metrics.

If there’s one thing this report illustrates, it’s the importance of continued information sharing and inclusion among and between academics, and between the private sector and academia. For instance, a comprehensive report from researchers at the Pacific Northwest National Laboratory in 2011 showed that algae grown in water from existing saline aquifers and recycling nutrients would be able to provide up to twice the goal for advanced biofuels set under the Energy Independence and Security Act goal (roughly 40 billion gallons, or 20 percent of annual transportation fuel demand). This information contradicts the conclusions drawn by the NRC report about water use.

As our industry continues to evolve, and as pre-commercial and demonstration facilities continue to come online, we will have even more information about the true techno-economic and sustainability measures of algae-derived fuels.

We welcome the evaluation and scrutiny regarding the sustainability of our industry, and move confidently forward knowing that sustainability is not just part of our industry’s DNA—it’s key to the ROI.